Great Encounters' name is based on the Moonlit Pursuit subset of the fourth Japanese DP expansion, beginning its transition into English-language sets. The set contains 100 cards from Moonlit Pursuit/Dawn Dash, with two Dialga, two Palkia and two Darkrai (one of each a LV.X) being held back from Shining Darkness, completing the 106-card set. The cards from Moonlit Pursuit/Dawn Dash that were not included in Great Encounters were later printed in Majestic Dawn.
In order for the fifth Japanese DP set, Cry from the Mysterious/Temple of Anger, to be released closer to the eleventh Pokémon movie (Giratina and the Sky's Bouquet: Shaymin), the set's release was delayed by three months, making a six-month gap between the release of it and the previous set. In order to prevent such a large gap in the English-language releases, Moonlit Pursuit/Dawn Dash was separated between two sets: Great Encounters and Majestic Dawn.
Great Encounters is also the first set to include Darkrai, containing its Moonlit Pursuit card and both its Shining Darkness cards (including the LV.X variant). Cresselia is the only LV.X card in the set to originate from Moonlit Pursuit/Dawn Dash; Darkrai, Dialga and Palkia were held back from Shining Darkness.